1. Technical Field
This invention relates to wireless telephones, and has particular relation to reduced power modes, such as when the telephone is in an RF-transmission-restricted environment, such as an airplane, or is being used in a mode of reduced activity, such as operating as an alarm clock.
2. Background Art
A wireless telephone (cellular, PCS, etc.) is sometimes in a situation (such as on an airplane) where transmission is prohibited. The conventional method for dealing with such situations is to disable the transceiver, either by hardware or software. The transmitter and receiver consume much of the power required by the telephone, so this method has the additional benefit of conserving the battery.
Similarly, the telephone may be used as an alarm clock. Since the user does not wish to receive calls while he is asleep, the transceiver is turned off, and the alarm clock feature continues. The alarm clock feature is distinct from the reminder feature, in which the telephone is configured to remind the user, during the day, of an upcoming appointment, and also is configured to receive and place calls as required. Turning off the transceiver provides a significant power reduction in alarm clock mode in comparison to remind mode. Later the alarm clock can turn the transceiver back on.
Applicants have noted that, while transmission and reception consume much of the power required by the telephone, there is a substantial power drain even when the transceiver is disabled. In particular, the wireless modem remains enabled even during airplane and alarm clock modes, when the transceiver itself is disabled. The present invention thus provides that both the transceiver and the modem be disabled, yet also provides that substantial other (and low power) apparatus be enabled during the airplane and alarm clock modes. For example, the user would continue to have access to the phone book, messages, and other phone features. Moreover, the alarm feature continues to function, as do alerts from calendar applets. This last feature is particularly important when the telephone is coupled with a personal digital assistant (PDA). If the telephone is not coupled with a PDA, then it is the modem function, rather than a separate modem per se, which is enabled or disabled. Such coupling is preferred, but not required, in the present invention.
Applicants accomplish this by having a low current counter (hardware) wake up the rest of the processor every 2.5 minutes. This 2.5 minute time period is adjustable. Usually the only thing the processor does is update the clock/calendar and go back to sleep. However, it can be set to automatically turn the phone on at a particular time, or to wait until manually commanded to turn the phone on.
The former choice is suited to an alarm clock mode. While the user is asleep at night, he does not want the telephone to receive calls, and therefore manually sets the telephone to alarm clock mode, so that he can continue to sleep. Alternatively, the user may select auto-entry, so that the alarm clock mode is automatically entered at a fixed time every evening. At some pre-determined time the next morning, the phone (modem and transceiver) turns on and allows incoming calls. This turn-on may be accompanied by an audible alarm, or may be silent. The phone exits alarm clock mode when the user commands an exit, at the alarm time, or when the user places an outgoing call, whichever happens first.
The latter choice is suited to the airplane mode. Even if the airplane is scheduled to land at 4:00 P. M., it is unwise to have the phone automatically turn itself on at that time. Planes often are late. It is far better for the user to wait until he is off the plane and in the terminal, and then manually turn the phone on. The phone exits airplane mode only when the user commands an exit. There is no fixed exit time, and the user is not permitted to place an outgoing call when the phone is in airplane mode.
In either mode, the phone book, calendar applets, etc. remain enabled.